The goal of the CTSN is to evaluate CT surgical interventions and related management approaches for the treatment of cardiovascular disease and conditions in adult patients. The network provides support to maintain an infrastructure to develop, coordinate, and conduct multiple collaborative surgical trials designed to improve cardiovascular outcomes and optimize post-operative neurological function. The aim of this research plan is to describe the experience, expertise, collaborative nature and resources of the University of Montreal cardiac surgery Clinical Investigation Group (UMCSCIG) which comprises the Montreal Heart Institute (MHI), Sacre-Coeur Hospital of Montreal (HSC) and The University Center of the Universite de Montreal (CHUM) that will substantially contribute, as in the first cycle of funding of the CTSN, to the success of the cardiothoracic Surgical trials Network. This University of Montreal Cardiac Surgery Clinical Investigation Group renewal application will be separated into three sections: 1) A description of the University of Montreal Cardiac Surgery Clinical Investigation Group; 2) The experience of the MHI, the PI-applicant and of the group investigators; 3) A description of particular characteristics and expertise that the U of Montreal group can bring to the larger NIH network.